Common Buzzard vs Red-tailed Hawk: identification by tail band and underwing

The subterminal tail band is where nearly everyone starts with this pair, and it is a weaker starting point than it looks. Common Buzzard Buteo buteo and Red-tailed Hawk Buteo jamaicensis are each their own continent’s default large raptor, they are closely related, and in the ordinary run of things they never see each other. One breeds across Eurasia, the other across North America. The question only arises when a bird turns up on the wrong side of the Atlantic — and by then the observer usually has a distant bird, poor light, and a strong expectation about which species it ought to be.

Common Buzzard vs Red-tailed Hawk: buteo identification without an overlap

The common buzzard vs red-tailed hawk problem is unusual in that it is almost never a live question. Both species are abundant and familiar within their own ranges, where nothing similar occurs, so neither is examined closely by the people who see them most. Familiarity in this pair does not transfer, and buteo identification learned on home ground is a poor guide to a bird that should not be there.

Two further complications make buteo identification harder here than the field guides suggest. Both species are extremely variable across their ranges, to the point where breeding pairs are frequently dissimilar. And a vagrant will not necessarily be an adult in clean plumage — it is at least as likely to be a juvenile, which is the plumage in which both species look most alike.

Which birds are actually involved

Neither name refers to a single consistent bird, and a comparison that treats them as two fixed types will fail on the individual in front of the observer.

Common Buzzard varies from pale, almost white-bellied birds through the ordinary mid-brown type to birds that are near-uniform dark chocolate, and that range occurs within single populations rather than only between them. On top of it sit the regional forms. The Steppe Buzzard, vulpinus, which breeds in eastern Europe and Siberia and winters in Africa, is smaller, longer-winged and often distinctly rufous, and it is the form that most nearly approaches the appearance of the hawk. Island populations in the Atlantic and the Mediterranean differ again.

Red-tailed Hawk is at least as variable and arguably more so. Eastern birds are the classic pale- bellied, red-tailed type; western birds include dark morphs that show no pale underparts at all; the very pale Krider’s type of the northern Great Plains has a whitish head and a washed-out tail; and Harlan’s Hawk, of Alaska and north-western Canada, is a blackish bird with a marbled greyish tail that has been treated at times as a separate species and looks like almost nothing else in the genus.

For a vagrant in Europe the population of origin matters. A bird crossing the Atlantic unassisted would most plausibly be an eastern bird, which is the form the field guides illustrate, while the western and northern types that most disrupt the comparison are the ones least likely to arrive. That is a probability rather than a rule, and it is not evidence about any individual bird.

The tail band, and where it fails

The feature everyone reaches for is the tail. An adult Red-tailed Hawk has a rufous tail that is largely unbarred, usually with a narrow dark subterminal band near the tip. A Common Buzzard has a greyish-brown tail crossed by numerous narrow bars, with a broader dark subterminal tail band at the end. Stated that way the difference sounds decisive.

It is not, for two reasons. The first is age: juvenile Red-tailed Hawks have brown, barred tails and no red at all, so the feature is simply absent on the birds most likely to be involved. The second is form. Steppe Buzzard, the vulpinus birds, can carry a washed rufous tail of their own — the one variation that pushes a buzzard towards the hawk, not away from it.

The useful refinement is to read what surrounds the band, not the band itself. A narrow dark subterminal tail band on an otherwise plain rufous tail says one thing; a broad subterminal tail band above a series of narrower bars across the whole tail says another. The presence of a band is not the information — the pattern of the rest of the tail is.

Underwing: the patagial stripe

The feature that actually decides most cases is on the underwing. Red-tailed Hawk shows a dark patagial stripe: a bar running along the leading edge of the inner wing, between the body and the wrist. Common Buzzard does not show it. The patagial stripe is present in juveniles as well as adults and across the pale morphs, which is precisely what the tail cannot claim.

Any common buzzard vs red-tailed hawk call therefore rests on getting an underwing view in reasonable light, and on a photograph of the underwing if one is possible. A perched bird photographed from behind, however sharp, may not settle it.

The belly is worth reading at the same time. Many Red-tailed Hawks show a dark band of streaking across the lower breast and belly, which supports the identification without proving it, since Common Buzzard is variable enough to produce something similar.

Ageing the bird, and why it changes the answer

Both species look most alike as juveniles, so establishing age is not a refinement to be added afterwards. It decides which features are available at all.

The most reliable age character on a soaring buteo is the trailing edge of the wing. An adult carries a broad, clean-cut dark band along the rear edge of the wing, produced by dark tips to adult flight feathers of even length. A juvenile does not: its flight feathers are narrower and more pointed, the dark tips are narrow, and the trailing edge reads as a thin dark line or a soft diffuse edge, not a band. The same difference gives many juveniles a translucent panel across the inner primaries that adults show far less obviously.

Tail shape helps in the same view. Juvenile buteos have relatively long, narrow tails with narrow feathers, and the whole bird can look longer-tailed and more lightly built than an adult of the same species. Eye colour is the third character, though it needs a close view or a good photograph: in Red-tailed Hawk the iris is pale greyish or yellowish in a juvenile and darkens to brown with age, and buteo eye colour generally darkens, not lightens.

The consequence for this pair is direct. A juvenile Red-tailed Hawk has no red tail, so the feature the whole comparison is popularly built on is missing exactly when the identification is hardest. The patagial stripe is present in juveniles, which is the reason it carries the weight the tail cannot. The same principle, that a plumage state decides which characters are usable, runs through the account of first-winter Mediterranean Gulls and, for wildfowl, through eclipse plumage.

Reading the whole underwing

The patagial stripe is the decisive mark, but it is easier to find when the rest of the underwing is being read as a pattern, not searched for one feature.

A Common Buzzard in a good light shows a pale panel across the bases of the primaries, a dark crescent at the carpal joint, a dark trailing edge whose width depends on the bird’s age, and underwing coverts that vary from almost white to dark brown. What it does not show is a solid dark bar running along the leading edge between the body and the wrist.

A Red-tailed Hawk shows that bar, and it is usually the darkest feature on an otherwise pale underwing. On dark-morph birds it is swallowed by the surrounding darkness and the mark becomes unusable, which is one of the reasons a dark buteo out of range is so often left unidentified. The annotated plate on this page sets the two underwings against each other with the patagial region marked on both, which is the comparison a field guide illustration of each species separately does not make.

Light matters more here than on most features. Against a bright sky the underwing is in shadow and a dark leading edge can be invented by contrast or hidden by it. The mark should be recorded from a view where the underwing is lit, and a photograph is worth far more than a long look.

What size does not tell you

It is tempting to fall back on measurements. Published figures do not support it. Length and wingspan ranges quoted for the two species overlap heavily, and the quoted ranges themselves differ between sources by enough to swallow the difference. Against a featureless sky there is nothing to compare a lone raptor with in any case.

There is a further reason to distrust it. Both species vary in size across their ranges and between the sexes, with females substantially larger than males in both, so the ranges quoted in a guide are already the sum of several overlapping distributions. A comparison of averages says nothing useful about two individuals, and the individual is what is being looked at.

Comparison with a second bird is the only version of the argument worth anything, and it is rarely available. A buteo alongside a Carrion Crow, a Herring Gull or a known Common Buzzard can be placed against something of known size; a buteo alone against cloud cannot, and observers consistently overestimate the size of a bird they are hoping is rare.

Structure is more useful than size. Wing shape in a glide, the depth of the hand, the way the bird holds its wings when soaring: these are worth recording, though they are supporting evidence rather than a decision.

The perched bird, and the bird in the air

Most of what is written about this pair assumes a soaring bird overhead. A good many are seen perched, and the two situations offer different evidence.

On a perched bird the underwing is unavailable, which removes the deciding feature, and the tail is usually seen only from above and often only partly. Two upperpart characters are worth checking in its place. Juvenile Red-tailed Hawks frequently show a pale V across the mantle, formed by whitish edges to the scapulars, which is conspicuous on a bird seen from behind. Common Buzzards commonly show a pale crescent across the breast, sometimes described as a necklace, which is a variable feature but a familiar one. Neither is diagnostic on its own, and a perched bird that shows neither has not been identified.

In the air, structure is worth recording and worth treating carefully. Both species soar with the wings held slightly above the horizontal, and the difference in that angle is one of degree rather than of kind, so it is supporting evidence at best. Both hang into a headwind, and Common Buzzard hovers readily enough that hovering says nothing. What is more useful is the shape of the wing itself: the relative length of the arm and the hand, how deeply the primaries are fingered, and whether the trailing edge of the wing is straight or bulges. Those are the characters a photograph of a soaring bird preserves, and a written impression of them made at the time is worth having alongside it.

The general point holds across the pair. The features that survive distance, poor light and a bird that will not turn are not the features the books lead with, and the working order below is built around that, not around what is easiest to describe.

The question that usually decides the record: where did it come from

For a Red-tailed Hawk in Europe, identification is frequently the easy half. Provenance is the hard half, and it is what most such records turn on.

Red-tailed Hawks are widely kept in falconry and in bird-of-prey displays in Britain and elsewhere in Europe, and birds escape. An escaped falconry bird is a genuine Red-tailed Hawk, correctly identified, and it tells an observer nothing about transatlantic vagrancy. Records committees therefore look past the identification to a second set of questions, and it is worth knowing what they are before the bird is out of sight.

Equipment is the clearest evidence: jesses, anklets, a transmitter mount, a bell, or the marks left where any of those were. A bird photographed with its legs visible has answered the question; a bird photographed from above has not. Behaviour is softer evidence but real. A bird that hunts from fence posts beside people, comes to a lure, or shows no reaction to close approach is behaving like a bird that has been handled. Plumage condition matters too: broken and abraded tail feathers in a pattern produced by a perch, or feathers repaired with imping, point the same way.

Timing and circumstance carry the rest. A bird arriving in autumn on the western seaboard alongside other American vagrants is in a very different position from one that appears inland in midsummer near a raptor centre. None of this is identification, and all of it belongs in the notes.

The other buteos in the question

It is worth naming the birds that turn a two-way comparison into a wider one, because a vagrant buteo is not automatically one of these two.

Rough-legged Buzzard occurs on both continents, which makes it the one large buteo an observer on either side of the Atlantic could genuinely meet, and its white tail base with a broad dark terminal band, dark belly and dark carpal patches are distinctive enough to be checked first rather than last. Long-legged Buzzard is a real possibility in southern and eastern Europe and has a pale unbarred tail of its own. In North America, Swainson’s Hawk and Red-shouldered Hawk are both regular sources of misidentified Red-tailed Hawks. Broad-winged Hawk has reached Europe, and a small buteo out of range is not a small Common Buzzard by default.

The practical instruction is the one the confusion pairs index applies throughout: the candidate set has to be decided before the features are weighed, because a feature that separates two species can be useless against a third that was never considered. A comparison of subspecific and regional forms runs the same way, as in the account of the eastern Common Gull, where the question is not which species but which population.

A defensible order of work

Read the underwing first and look specifically at the leading edge. Then take the tail, from above and below, noting whether barring runs the length of it or is confined to a band near the tip. Then the belly. Then structure. Size last, or not at all.

In practice a common buzzard vs red-tailed hawk claim needs the underwing, and views that do not deliver it do not deliver an identification. Recording the bird as an unidentified buteo is an honest outcome and a common one — a vagrant seen briefly and badly is not made identifiable by wanting it to be.

What that record should contain is worth being specific about, because the bird will not be available to check later. Note the underwing and whether the leading edge was lit or in shadow; the tail from above and below, describing what the barring does along its whole length, not only near the tip; the width and definition of the dark trailing edge, which is the age character; the legs, if they were seen at all, and whether anything was attached to them; and the light, angle and distance the whole thing was seen at. A description assembled that way can be assessed by someone else. A description that says “clearly a Red-tailed Hawk” cannot, and it will not survive the first question anyone asks of it.

1. 1 Patagial bar — a dark bar along the leading edge of the inner wing, between body and wrist. Red-tailed Hawk has it at all ages; Common Buzzard does not. The single most useful feature in the pair.
2. 2 Carpal patch — a dark comma at the wrist against a paler underwing, typical of Common Buzzard. Present on many birds but not all, so it supports a call rather than making one.
3. 3 Barring across the whole tail — Common Buzzard: narrow bars the full length, then a broader dark band at the tip. It is the barring above the band that identifies it, not the band.
4. 4 One band on a plain tail — adult Red-tailed Hawk: unbarred above a single narrow subterminal band. Juveniles have brown barred tails and lose this feature entirely.